Amid the Latest Criticism, Herbalifers Stay Resolute

When hedge-fund manager William Ackman unveiled his 334-slide presentation alleging that Herbalife Ltd. is a pyramid scheme, it did nothing to shake Joanne Clare.

The 38-year-old Staten Island mother of three has been selling the company's weight-loss products and supplements since 2004, when she says they helped her drop from 210 to 160 pounds in four months. She now sells as much as $3,500 a month of Herbalife products to her 30...